Specific pattern of cell cycle during limb fetal myogenesis
Specific pattern of cell cycle during limb fetal myogenesis
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DOI：
10.1016/j.ydbio.2014.05.015
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发表时间：
2014-08-15
影响因子：
2.7
通讯作者：
Duprez, Delphine
中科院分区：
文献类型：
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作者：
de Lima, Joana Esteves;Bonnin, Marie-Ange;Duprez, Delphine
细胞增殖和分化的严格调节是确保发育和出生后生命期间正常生长所必需的。调节细胞增殖的信号的来源和性质在体内没有很好地确定。我们研究了小鼠肢体中增殖细胞的特定模式，使用基于荧光泛素化的细胞周期指示剂（Fucci）系统，该系统允许分别以红色、黄色或绿色荧光颜色显示细胞周期的G1、G1/S转换和S/G2/M期。我们还使用逆转录病毒RCAS系统在鸡胚中表达Fucci盒。我们使用Fucci转基因小鼠对胎儿肢体肌肉、成人成肌细胞原代培养物和分离的肌纤维培养物中的肌源性细胞的细胞周期状态进行了全面的分析。我们发现，终末分化的肌纤维的肌核显示富奇红色荧光在小鼠和鸡胎儿的发展，在成人分离的肌纤维（离体）和成人成肌细胞（体外）小鼠培养。这表明肌核在G1期退出细胞周期，并维持在阻滞的G1样状态。我们还发现，处于G1期的周期性肌肉祖细胞和成肌细胞并没有完全被Fucci系统所覆盖。Fucci系统标记的Pax 7+细胞在小鼠胚胎肌细胞发生过程中主要分布于S/G2/M期。在小鼠胚胎肢体中，S/G2/M期的增殖细胞显示出特定的模式，描绘出个体化的肌肉。此外，我们观察到更多的Pax 7+细胞在S/G2/M期的肌肉尖端，相比，中间的肌肉。这些结果突出了一个特定的空间区域化的循环细胞在肌肉边界和肌肉肌腱界面在胎儿发育过程中。(C)2014爱思唯尔公司All rights reserved.
Tight regulation of cell proliferation and differentiation is required to ensure proper growth during development and post-natal life. The source and nature of signals regulating cell proliferation are not well identified in vivo. We investigated the specific pattern of proliferating cells in mouse limbs, using the Fluorescent ubiquitynation-based cell-cycle indicator (Fucci) system, which allowed the visualization of the G1, G1/S transition and S/G2/M phases of the cell cycle in red, yellow or green fluorescent colors, respectively. We also used the retroviral RCAS system to express a Fucci cassette in chick embryos. We performed a comprehensive analysis of the cell cycle state of myogenic cells in fetal limb muscles, adult myoblast primary cultures and isolated muscle fiber cultures using the Fucci transgenic mice. We found that myonuclei of terminally differentiated muscle fibers displayed Fucci red fluorescence during mouse and chick fetal development, in adult isolated muscle fiber (ex vivo) and adult myoblast (in vitro) mouse cultures. This indicated that myonuclei exited from the cell cycle in the G1 phase and are maintained in a blocked G1-like state. We also found that cycling muscle progenitors and myoblasts in G1 phase were not completely covered by the Fucci system. During mouse fetal myogenesis, Pax7+ cells labeled with the Fucci system were observed mostly in S/G2/M phases. Proliferating cells in S/G2/M phases displayed a specific pattern in mouse fetal limbs, delineating individualized muscles. In addition, we observed more Pax7+ cells in S/G2/M phases at muscle tips, compared to the middle of muscles. These results highlight a specific spatial regionalization of cycling cells at the muscle borders and muscle-tendon interface during fetal development. (C) 2014 Elsevier Inc. All rights reserved.